How the Leipzig research community organized itself

In the last section of chapter 2 we took note of the fact that the establishment of psychological laboratories involved the institutionalization of certain social arrangements. Psychological experimentation became a collaborative effort dependent on a division of labor among individuals who carried out different functions in the experimental situation. More specifically, a broad distinction emerged between those who acted as the human source of psychological data, the experimental subjects, and those who manipulated the experimental conditions, the actual experimenters. Although this distinction was essentially a response to the practical exigencies of late nineteenth-century “brass instruments” experimentation and not the product of deep reflection, it rapidly became traditionalized. To carry out sophisticated experiments with relatively complex apparatus, one now had to assign the function of data source and the function of experimental manipulation to different people.

What was not noticed at the time, or indeed for almost a century afterward, was that this arrangement created a special kind of social system – one of psychological experimentation. The interaction between subjects and experimenters was regulated by a system of social constraints that set strict limits to what passed between them. Their communication in the experimental situation was governed by the roles they had assumed and was hedged around by taken-for-granted prescriptions and proscriptions.

However, the specific features of this social system were not necessarily fixed. The basic division of labor between experimenters and subjects still left much room for local variation. For instance, there was nothing in the practical requirements of psychological experimentation that dictated a permanent separation of experimenter and subject roles.

What this book is about

What exactly constitutes a field like scientific psychology? Is it constituted by its most innovative and influential contributors; by the scientific findings that it has produced; by the theories it has elaborated; by its concepts, techniques, or professional associations? Obviously, all this and more goes into the making of a field, but most of us would probably see some of these components as playing a more essential role than others. Even if were fuse to commit ourselves explicitly we are likely to imply that certain components define the field more effectively than others by the way we organize our knowledge. For example, in the systematic presentation of information derived from the field of psychology or one of its parts, the material is most commonly organized in terms of prominent contributors, important findings, or influential theories. A perhaps unintended message of such communications is that psychology is its theories, is its findings, or is its individual contributors.

The way in which we organize a field will determine the way we organize its history. If we see the field of psychology as essentially an aggregate of individual contributors, we are likely to treat the history of the subject in terms of a succession of prominent figures. If psychology is its theories or its findings, then its history will become a history of psychological theories or psychological findings. Our organization of the history of the field will also serve as a subtle justification of the way we have characterized the field in the present.

Human sources for psychological generalization

Making psychological knowledge claims, we saw in the last chapter, involves an ordered set of attributions attached to a particular kind of subject. The significance of these attributions depends in a crucial way on the nature of the subject whose attributes they are claimed to be. If the subject is an individual consciousness, we get a very different kind of psychology than if the subject is a population of organisms. The gradual predominance of the latter type of subject was seen to depend on the interest of psychologists in a type of knowledge that was applicable to populations outside the laboratory but that was as abstract as the generalizations of the physical sciences. This meant working with artificially defined collective subjects in the research situation and then imposing these definitions on people outside the laboratory.

In other words, psychological research on populations had a tendency to replace the social categories that defined populations in real life with populations defined in terms of nonsocial categories. American psychology aimed to be a socially relevant science, but not a social science. Its approach was to be that of a natural science, although its ultimate field of application was to be found among members of real societies. Thus, research on socially defined populations came to be regarded as “applied” research, whereas “basic” research worked with abstract populations. In the extreme case the populations need not even be human. In fact, white rats fulfilled the role of a population of completely abstract organisms more adequately than any human population could hope to do.

Knowledge claims and attributions

Modern psychology may have started out with at least three different types of investigative practice, but, as we have seen, one of these hardly survived the first few decades in the history of the discipline. Among the other two, it was the Galtonian type that was to achieve a dominant position during the first half of the twentieth century. In the following chapters we will have to analyze various aspects of this complex historical development. Our analysis will draw heavily on the information contained in the psychological journals that now provide the major vehicle for the establishment of psychological knowledge claims. Twentieth-century psychology is a system of “public knowledge,” and the major disciplinary journals constitute the crucial link in the transformation of the local knowledge produced in research settings into truly public knowledge.

This transformation involves the preparation of a research report that meets the criteria and conventions that prevail within the discipline or research area. Ostensibly, the research article communicates certain “findings” held to represent knowledge by the conventions of a particular community. In fact, the contents of the article only represent a knowledge claim, which may or may not be accepted by its intended audience. To convince this audience, the authors must submit to its conventions. For instance, they must adopt a certain literary style, relate the contents of the article to known concerns and interests of its possible audience, demonstrate the conformity of their methods to prevailing norms, and so on.

All but one of the tables that appear in chapters 4, 5, 6, and 8 summarize parts of a content analysis of empirical articles published in psychological journals during the discipline's early years. The selection of journal volumes and articles for inclusion in this analysis was based on the following considerations.

Four basic reference points – 1895, 1910, 1925, and 1935 – were chosen for the purpose of establishing time trends. Journal volumes published during those years were included in the analysis as were the immediately preceding and the immediately following volume. For each set of three consecutive volumes of a journal, the results of the analysis were pooled to allow for minor fluctuations from one year to the next. This yielded data for the periods 1894–1896, 1909–1911, 1924–1926, and 1934–1936. There were minor discrepancies, as when the results of the analysis of the first three volumes of a journal that began publication in 1910 were included in the 1909–1911 period.

Only one of the journals analyzed, the American Journal of Psychology, provided a source of empirical articles over the entire period. The other journals began publication at a later stage or ceased publishing empirical studies in significant numbers at some point. The second decade of the twentieth century was a particularly fertile one in terms of the appearance of new American journals. For tracing changes in these journals the 1910 reference point was therefore impractical.

The birth date of modern psychology is usually placed toward the end of 1879 when Wilhelm Wundt designated some space at the University of Leipzig to be used for the conduct of psychological experiments. Of course, the date is arbitrary, as are all such birth dates for disciplines. This arbitrariness arises less from the rival claims of other locations or individuals than from the obvious fact that the birth of a discipline is not a singular event but a complex process extending over a considerable period of time. In the case of psychology the relevant period extends both before and after the magic date.

When psychology became an autonomous field of research it did not invent its concepts and problems out of the blue but took them over from already existing fields like philosophy and physiology. Similarly, the practical activities that came to be identified as methods of psychological re-search were anything but completely new inventions. They were more in the nature of adaptations of already existing practices to a somewhat different context. Those who laid the foundations of a new psychological research tradition were constrained at every step by the traditions of investigative practice with which their general cultural experience or their personal training had made them familiar. The best they could do was to modify these practices, sometimes in quite minor ways, to suit the new goals they had in mind.

The preceding analysis of the historical development of investigative practices in psychology is obviously based on a certain model of the investigative process. Although various aspects of this model have emerged in previous chapters, some of the basic features of the model still need to be made explicit. The first part of this chapter is devoted to this task. In the remainder of the chapter I briefly address some general questions pertaining to the status of psychological knowledge that arise out of the kind of analysis presented here. These questions all revolve around the issue of how the social construction of psychological knowledge affects the reach of the knowledge product. Although knowledge claims are generated in specific sociohistorical situations, it does not follow that they have no significance or validity beyond those situations. There are two possibilities here. First, psychological knowledge may be generalizable to situations other than those in which it was generated. This is the question of applicability. More fundamentally, however, there is the possibility that psychological knowledge claims may be able to tap a level of “psychological reality” that is independent of the special conditions under which it is investigated. The second and third sections of this chapter discuss these possibilities.

The political economy of knowledge production

Investigative practices are part of a productive work process. Their employment results in the generation of valued products, though of course these are not primarily material but symbolic products – namely, scientific knowledge claims. This same employment necessarily involves people who put these practices to work and also some kind of raw material that is productively transformed into the valued knowledge product.

Historical studies of the sciences tend to adopt one of two rather divergent points of view. One of these typically looks at historical developments in a discipline from the inside. It is apt to take for granted many of the presuppositions that are currently popular among members of the discipline and hence tends to view the past in terms of gradual progress toward a better present. The second point of view does not adopt its framework of issues and presuppositions from the field that is the object of study but tends nowadays to rely heavily on questions and concepts derived from studies in the history, philosophy, and sociology of science. A history written from the insider's point of view always conveys a strong sense of being “our” history. That is not the case with the second type of history, whose tone is apt to be less celebratory and more critical.

In the case of the older sciences, histories of the second type have for many years been the province of specialists in the history, philosophy, or sociology of science. This is not, or perhaps not yet, the case for psychology, whose history has to a large extent been left to psychologists to pursue. Accordingly, insiders' histories have continued to have a prominence they have long lost in the older sciences. Nevertheless, much recent work in the history of psychology has broken with this tradition.

Education as psychology's primary market

Thus far, we have traced the development of some of psychology's investigative practices in terms of the general knowledge interests pursued by psychologists. This may be adequate for the more general features of these practices but when we turn to more specific features it becomes necessary to take into account a broader social context. The fact is that almost from the beginning of the twentieth century psychology ceased to be a purely academic discipline and began to market its products in the outside world. That meant that the requirements of its potential market were able to influence the direction in which psychology's investigative practices were likely to develop. Practices that were useful in the construction of specific marketable products were likely to receive a boost, whereas practices that lacked this capacity were henceforth placed under a handicap.

Of course, the requirements of the market did not act on a passive discipline. Not only did many psychologists actively court practical application, but these efforts would have led nowhere if the discipline did not have at its disposal certain techniques that lent themselves to the development of a socially useful product. In the present chapter we will analyze two such techniques in terms of their significance for a socially relevant investigative practice: the Galtonian approach to individual differences and the experimental use of treatment groups. Both of these methodological innovations assumed enormous importance in the subsequent development of modern psychology, but it is doubtful whether this would have been the case had they not played a crucial role in the constitution of psychology as a socially relevant discipline.

Extension of the mental test model

American psychologists, as we noted in chapter 7, had set about redefining the psychological problem of individual differences in terms of a comparison of performances against a competitively defined standard. This redefinition appeared to be perfectly adapted to the administrative requirements of social institutions whose efficient functioning depended upon some kind of selection process that was rationally defensible. The kinds of tasks that best lent themselves to the measurement of individual differences in this sense were tasks with answers that were unambiguously right or wrong. Performance on such tasks could be readily arithmetized by counting right and wrong answers, a procedure that had long been conventionalized in the institution of school examinations. Improvements in the precision of such procedures, made possible by Galton's fundamental contributions, eventually led to the construction of normed intelligence tests.

It is hardly a cause for surprise that educational institutions provided the setting in which intelligence tests proved themselves best adapted to administrative requirements. Transferred outside their home ground, their ability to predict future performance was much diminished, often to the point where their practical usefulness vanished altogether. This problem already emerged in the first major attempt at employing intelligence tests in the service of a noneducational institution, the U.S. Army in World War I. Most of the psychologists involved appear to have been convinced of the potential applicability of intelligence tests to military selection problems. However, although they were given considerable leeway and succeeded in testing well over a million men, the army does not seem to have found the results of this exercise particularly useful.

Interpreting the professional project

The previous chapters have provided abundant evidence for the fact that the historical development of psychological research practice did not proceed along a single track. At the very least, there were two different lines of development. By the 1920s the Wundtian style of experimentation, with its roots deep in the philosophical and scientific traditions of the nineteenth-century German university, seemed to constitute a deteriorating research program within American psychology. As it was fast losing its appeal for all but a few practitioners, the Galtonian research program, strongly linked to practical rather than academic concerns from the beginning, was moving from strength to strength. Not only was it extending its appeal with every passing year, but, as we have seen, it proved itself capable of generating exciting methodological innovations that promised to extend the scope of scientific psychology far beyond what had hitherto been thought possible.

We have also seen that the galloping success of the Galtonian program was in no small measure due to its very direct link to the demands of a significant extradisciplinary market for its products. Nevertheless, it would be a mistake to see the development of a certain style of investigative practice as an essentially passive adaptation to external social requirements. That might have been true of certain individuals, but it was not true of the response of the discipline as a whole. Even on an individual level most practitioners recognized that practical successes would be short lived if they threatened to undermine the prestige of the disciplinary enterprise they represented.

The title of this book might suggest an unthinking adherence to the roles of experiment in science and an unquestioned faith in experimental results. This is not the conclusion I want the reader to reach. At the very least, the reader should firmly believe in both the fallibility and the corrigibility of science. I also want the reader to be persuaded that the evidence model, in which questions of theory choice, confirmation of theory, or refutation of theory are decided on the basis of valid experimental evidence, is both an accurate description of the way science is practiced, and a philosophically justified view.

There are episodes in which the experimental results are still unchallenged and regarded as correct. Thus, the experiments of Wu, Ambler, Hayward, Hoppes, and Hudson; of Garwin, Lederman, and Weinrich; and of Friedman and Telegdi provided the crucial evidence that established the hypothesis of parity nonconservation, suggested by Lee and Yang. The discovery of parity nonconservation played an essential role in the development of the V-A theory of weak interactions. It was also incorporated into the Weinberg-Salam theory the successor to the V-A theory. The experiments on atomic parity violation were regarded as extremely important, if not crucial, tests of that theory. I suspect that had the results not agreed with the Weinberg-Salam theory the theory would have been discarded, or at least severely modified.

The fallibility and corrigibility of experimental results, of theoretical calculation, and of the comparison between experiment and theory will be amply illustrated in the episode to be discussed. This section will deal with the relation between experiment and theory in the field of weak interactions during the period between Fermi's proposal of his theory of β decay in 1934 and the acceptance of the V-A theory of weak interactions in 1959. Part of the fascination of this story is that the V-A theory appeared to be refuted by existing experimental evidence at the time it was proposed by Sudarshan and Marshak (1957) and by Feynman and Gell-Mann (1958). The authors, themselves, recognized this and suggested that the experimental results might be wrong, a suggestion that turned out to be correct. Nevertheless the theory was proposed because it seemed to be the only available candidate for a universal theory of the weak interaction. In this section I will examine the origin and development of this idea of a universal theory of the weak interaction to the acceptance of the V-A theory as such a theory.

Fermi's (1934a, 1934b) theory of β decay was introduced in 1934. It was not the first quantitative theory of β decay. Beck and Sitte (1933) had formulated an earlier theory using Dirac's prediction of the positron. According to their 1933 model an electron–positron pair was created. The positron was absorbed by the nucleus and the electron emitted (or vice versa).